Method and means for perforating well casings



April 27,1926. '1 1 1,582,184

S. W. MIMS METHOD AND MEANS FOR PERFORATING WELL CASINGS Filed March 3,1924 Patented Apr. 27, 1926. i

UNITED STATS `SIDNEY W. m8, 0F LOS ANGELES, CALIFORNIA.

METHOD AND `MEANS FOR PEREORATING WELL CASTINGS.

Application led March 3, 1924.v Serial No. 696,454.

lTo all 'whom it may concern.'

Be it known that I, SIDNEY W. MIMS, a citizen of the United States,residing at Los Angeles, in the county of Los Angeles and State ofCalifornia, have invented a new and useful Method and Means forPerforating Well Casings, of which the fol lowing is a specification.

This invention'relates to a method and means for perforating well casingand refers particularly to a method and means for perforating wellcasing in place in a well hole.

'In the construction and operation of oil Wells ila-frequently becomesnecessary to perforate a pipe or casing in place in the well hole anddisposed' at a considerable distance from the top of the well hole. Theart has found considerable diiiculty in properly opening such wellcasing or pipe. One example of the necessity of opening such holes isencountered where a. casing has been cemented in a well hole for thepurpose of shutting olf the water from the oil sand and it is then foundthat the shut oif of water is not complete and it is desired to open thecasing at another point to permit further cement to be forced behind thewell casing so as to complete the shut ofi'. Moreover, in certain oilfields the oil wells have been originally drilled to upper oil sandwhich at the start of the history of the oil field produced less oilthan the lower oil sand and accordingly a great number of wells havebeen drilled through the first oil sand, the well pipe then cemented toclose .u p the well formation, and the well .then bored below such upperoil sand into the lower oil sand with an additional casin employed forreaching to the lower oil san As the lower sand becomes exhausted it isdesirable to again open the well into the .upper oil sand, and' for thispurpose it is necessary to perforate both well casings at the same time.

An object of this invention. is'to provide an improved deviceforperforating well casings and to provide such va device as will form aclean hole through the well pipe leaving the pipe or casing undamagedand strong around the perforations and to provide such a method andmeans as can be used to perforate even double the wall cas. ing in placein a deep well.,

Other objects and advantages of the inventionwill be' apparent from thedescription of the invention in its preferred form or embodiment.

Reference `is therefore had to the accompanying drawings, whichillustrate a device whichma be .used to carry out my preferred methodofperforating a well pipe or casing in place in` an oil well.

Figure 1 is an elevation in vertical section through a well holedisclosing the manner of perforating a well pipe or casing in order tore-cement the well.

Fig. 2 is an enlarged elevation mainly in vertical section ofthe body ofthe perforating device shown in- Fig. 1.

Fig. 3 is an end elevation of a modified form of thel device.

Fig. 4 is an elevation at right angles to Fig. 3 and mainly in verticalsection.

ig. 5 discloses another sectional view of a well hole in this case`illustrating the double wall casing which may be perforated by thedeviceand method of a further modifcation of this invention.

Fig. 6 is an enlarged view of this further modification of theperforating device mainly in vertical section.

Referring first to Fig. 1, the 1 indicates a well casing or pipe inplace in a well hole, which pipe has 'previously been cemented so thatcement indicated at 2 lies outside of the well casing 1, between thecasing and the formation 3. In such a Well hole the small passages suchas 4 may open up between the cement 2 and well casing 1.

By my invention such passages 4 may be sealed up by first perforatingthe pipe 1 by a perforating device 5 and then forcing cement through theperforations produced to seal such passages 4.

In Fig. 2 the perforating device is shown in one of vits preferredforms, such perforating device comprising a body 6 of steel or othermetal .having a chamber 7 in its center. 8 indicates a number of lateralwa s extending from the outside of the bo y 6 to the center of thechamber 7 which receive slugs 9 of a size to closely fit the ways 8 andpreferably provided with pointed ends 10 fastening the outside of thebody 6. The slugs 9 extend 'a distance within the chamber 7 and thereengage anvils 11 shaped to fit the chamber 7 and slide therein, saidanvils 11 vbeing normally held by .the slugs 9 a distance from the sidewalls of' the chamber 7 and being spaced apa-rt to provide a centralexplosive chamber 12.

The central explosive chamber 12 is filled with an explosive material 13such as trinitrotoluene or blasting gelatine and has embedded therein adetonating cap 14, the cap 14 being provided with electrical means 15 bywhich the cap can be exploded from the to of the well.v The body 6 isprovided with a vertical bore 16 extending upwardly from the center ofthe chamber 7 by which the explosive charge may be inserted into thespace between the anvils 11, and a plug 17 is threaded into the bore 16to close the opening and also to provide a handle 18 by which the devicemay be raised and lowered within the well casing 1. Duets 19 are alsolprovided in the body 6 lea-din from the outside to a point normallyclose by the anvils 11l but adapted to be uncovered when the anvils 11are forced to the side walls of the chamber 7 When em loying this formof the invention the bo yy and parts carried thereby are lowered upon aline, such as 20, down to the position within the well hole where theperforations are to be made. The c ap 14 1s then exploded by means of anelectrical lead 15 which causes an explosion of the mam charge betweenthe anvils 11. The explosionof such char e throws the anvils 11 to theside walls of t e chamber 7, the4 anvils 11 thus shoot the slugs 9 fromthe body of thel perforating device which then pass through the wellcasi-ng 1 leaving a clean form of pel.'- foration therein. The body 6 isof course made of sufficient strength to resist the force of theexplosive charge 13. The anvils 11 arriving at the sides of the chamber7 open the ducts 19 so as to permit an' escape of the gases throughsuch. ducts.-

In the form of the invention` shown in y Figs. 3 and 4 the perforatingdevice comprises a body 21 having a groove 22 therearound which receivesa strap 23 to which'a line may be attached for raising andv lowering thebody 21 within the well hole. The body 21` is bored out as indicated at24 from one side thereof to provide a chamber for lholding an explosivecharge. and 'directing the force ofthe explosive laterally from theperforating device andagainst a well casing, the ex losive 25 `eitherentirelyk il 'ng the inner end of t e bore, the outer end being closedby a slug 26-havilng a pointed end 27. Near the end of the bore 24 adetonatin cap 284 is imbedded in the ex losive 25 an a vertical passage30 to the top o the we l.

The vertical passage 30 communicates with the bore 24 and receives aplug 31 closing the passage, packing mate-rial 32 preferably beingposltloned between the -plug 31 and the explosive charge 25. v.

This embodiment of the mventwn diiiera rilling the bore or connected towires 29 leadin t rou h y well casing from the precedin method as iteliminates the anvils 11 whic are not necessary to all forms of theinvention and moreoverhas a uniform bore chamber 24 and may, if desired,dispense with the use of the slug 26. The slug 26 may be eliminated,since the force of the explosive charge is so confined by the body 21and directed to the discharge from said body, that when such slug 26 iselimlnated the force of the explosive charge is directed againstthecasing and perforates the same by burning therethrough, as will be morefully pointed out in connection with the embodiment illustrated in Fig.6.

The form of the invention shown in Fig. 6 has an inverted T-'sha-pedbody 32, the 1ower end of which is provided with a bore 33 extendingfrom end to end of the body and the upper portion being provided with abore 34 communicating with the bore 33 and enlarged at its upper end asindicated at 35 to recelve a plug 36. The smaller end of the bore 34receivesa casing 37 closely fitting the bore 34 and holding a detonatingcap 38 the cap 38 being connected with electrical leads 39 by which itmay4 be fired. The lower bore 33 is preferably filled from end to endwith an explosive charge. This form of the invention is preferable whendis nsing with 'the slug. The detonation o the cap 38 will cause theexplosive in the bore 33 to perforate a well pipe by burning through thepipe as the body 32 ismade v'of' Vsuflicient strength to resist theforce of the form of the invention as shown herein, and

various modications may be made without departing from the spirit of theinvention, and ,the invention is ofthe scope set forth in the appendedclaims.

I claim:

1. The method of ing in place in a wel lowering an vex losive chargedown the well casing inside o a .body of sufficient strength to resistthe ex lesion of the charge and having openings or directing the forceof the explosion out against the well casing, and lhen firing the chargein place in the well o e. l

2. A method. of perforating a well casing perforating a wellj casinplace in awell hole, which comprises lowi ering an explosive charge'down the well casing, exploding the charge, and directing the force ofthe charge in the direction of the and thereby perforating the same.

.3. A device fof raming a Wuming hole, which' comprises. .115

1n place within a Well hole, .which device comprises a body, anexplosive charge Within the body, said body having means for directingthe force of the explosive against a Well casing, and being ofsuilicient strength to resist the destructive force of said charge, andmeans for detonating the charge when lowered down in a Well hole.

4. In a device forvperforating a Well cas-1 ing in place in a Wellhole,'the combination of an explosive charge, a body holding theexplosive charge, said body being sufficiently strong to resist theforce Yof the explosive charge, lateral Ways for directing the force ofthe explosive towards the well casing, slugs normally closing the Ways,and means for detonating the explosive in place in a well hole.- v

i 5. A device for perforating a Well casing when in place in a Wellhole, Which device comprises in combination a metal body adapted forholding an explosivecharge,

ways for directing the force of the explosivelaterally against the Wellcasing, slugs normally closing the Ways, anvils between the slugs andexplosive, and means for detonat- 'lng the vexplosive in place Withinthe Well ole.

6. A device for perfora-ting a Well easing when in place in the Wellhole, comprising a body adapted .to hold an explosive charge, said bodybeing lowerable Within the Well casing, and having means for directingthe force of the explosive against such Well casing when suspendedtherein, the body being of sulicient strength to resist the destructiveforce of said charge, and means for suspending and detonating the chargein place in a Well hole.

Signed at Los Angeles, California, this 25th day of February, 1924.

SIDNEY W. MlMS.

